Method and mold for forming plastic insignia



Sept. 4, 1951 R. J. RENHOLTS METHOD AND MOLD FOR FORMING PLASTIC INSIGNIA Filed Aug. 5, 1949 FIEUE E FIRES-E R.5 mu o NH mm R l Y o 4 R V. B 1 2 F 4 3 m 3 w J h w u ln a 2 4 Patented Sept. 4,, 1951 METHOD AND MOLD FOR FORMING PLASTL IC INSIGNIA Roy J. Renholts, Oakland, Calif., assignor to Friden Calculating Machine 00., Inc., a corporation of California Application August 5,1949, Serial No. 108,849

4 Claims.

This invention relates to the afixing of plastic name plates, trade-marks, or other insignia, upon an article.

An'important object. of this invention is to provide a method and means for molding trademarks, name plates, or other indicia on the cover of an article in such a manner as to make its accidental removal impossible and still to avoid any damage to the plate upon which the indicia is applied. 7

Another object of this invention is to provide a method and means for applying letters or individual characters forming an insignia to an article in one simple operation.

A still further object of this invention is to provide'a method and apparatus for ainxing individual letters or insignia to a bearing plate without injuring or marring the painted surface of the plate.

These and other objects of this invention will be apparent from the description and claims which follow.

The invention will be readily understood from reference to the drawings in which- Fig. 1 illustrates the outside. or visible, portion of a mark as applied according to my invention.

Fig. 2 shows the reverse side of the mounting plate.

Fig. 3 is a cross-sectional view of the insignia of my invention, such as taken along the plane indicated by the line 3-3 of Fig. 1.

Fig. 4 is a cross-sectional view of the dies in position for moulding an insignia on a mounting plate, such as taken along the plane indicated by the line 4-4 of Fi l.

Briefly, my invention comprises providing a plurality of apertures through the plate or article within the outline of the insignia, pressing a pair of opposed dies against the two sides of the plate (the die on the outside being formed in the shape of the characters desired), and injecting a plastic material into the other die, through the apertures, and into the outside die. In this manner the characters are formed in situ, are separated on the outside but have a single locking strip.

along the back. Obviously, the formation of such an insignia takes-only a few seconds, and can be applied without injury to the article as will hereinafter be described.

The closest prior art with which I am familiar is the pre-forming of a plastic insignia provided with two or more bosses which are manually inserted through holes in the mounting plate. After manual insertion of the bosses in the holes in the mounting plate, theassembly is turned over and heat treated to expand the end of the bosses and thus in effect rivet the plastic insignia onto the metal plate. ihis prior art treatment has the disadvantage that there is considerable waste of plastic material in the pre-forming of the insignia in the fact that several handlings are necessary, which increases the cost thereof and in the fact that the insignia is attached to the plate in only two or three places so that it can readily be torn off or broken, as it is possible to catch a thread of a dustcloth under such insignia and loosen it from the cover plate. In my invention I form the insignia in situ in a single operation which takes perhaps ten seconds. I, therefore, avoid the extra handling of the plate and of the insignia. Also, in the old art, the holes through the plate had to be accurately positioned and carefully reamed as a burr would prevent insertion of the boss through the hole, while with my invention burrs and the like serve to anchor th 'insignia more firmly. More important, with my invention, the characters can be separated as shown in Fig. 1 which gives a more pleasing appearance than is possible when an insignia or name is written in script or mounted upon a backing plate.

A still further advantage of my invention lies in the fact that the several characters fit very tightly against the article-in fact with what may be termed a pressure fit. Each character is so firmly ailixed to the metal plate so that it is not only impossible to injure them by dusting, but it is impossible to insert a knife blade between the character and the plate. The only way in which the characters of my invention can be broken from the mounting plate is by use of a pair of pliers to twist them off or by use of a chisel. y

In its preferred form, my invention will be utilized to afilx a plurality of separate characters, letters, or insignia to an article or to the plate enclosing it. This permits the tradename or trade-mark, which is customarily used for this purpose, to show a plurality of separated letters, or characters, each of which appears in its individual, or disconnected, form, although the entire group operates as a single insignia. It will be understood, however, that my invention is also applicable to the affixing of a single letter, character, or insignia to an article.

In my invention the several insignia, or characters, which comprise the name, or other indicia, are mounted on a plate H) which, as shown in Fig. 3, may be coated with a painted finish II.

I haveused my invention with good results on plate I provide "a' plurality" of spacers 41 separ'a 3 the afilxing of a name to a cover plate painted with a wrinkle finish paint, the entire name being affixed with a single simple operation and without injury to the finish.

Cover plate In is provided with a plurality of apertures L ar anseaw th ha utl n at respective 'charadtrs I which comma the" some; plete insignia. "Ihes apertures maybe formedby stamping during the forming of the plate Ill, or ,i

plate.

With my invention the holes [5 can be of anyi-i-i size or shape and do not have to be reamed. As a matter of fact, any burrs thatni ti'clgtojthe holes as originally punched or drilled, merelya'dd' 1'5 to the strength of the bond between the mounting plate and the character.

A pair of opposed dies are temporarily applied, to the plate It] in a zone in which the platis' of substantially uniform thickness, as shown in Fig. 4. The outsidedietiq is providedWitlraplurai-lity' of "separated; or fdisc'crnnectedfcavitiesii l cor respondingto thefc'haracters- Z O'Whi-chit is de sired to mount onthe outsidetbf the-'-platerNor-*- mall'y these characters '2 ll tvillfbe lettersl-or other 'fl characters, arranged to forrn aflcomplete'nameor trademark. Against theb'aci "of the; plateifl a ec i e-32 is ap i ri n cs fi r o dieiflf" Preferably-the die SZ will-be provided with a single cavity; or channeljwhich encom passes; all of the apertures "l' An"'injecticn duct 34 "leads" to the" inner "die cavity: j The "two dies .are in opposed*relationshipon opposite sides of thep lat'e l0 and theplate-flfl is so positioned-in :respect' to them'"tha't"theapertures, i5 lie within 3 'theoutlin'esbf thecavitiesfl "in "thefdie' as=a11d--- "within the outline of thechannel arm the dieQL-f .A fluid plastic materialis then --injected through-= the duct 34 with sufil'cienfipressure to force the plajstic materialfthrough channel '33,"-'through-"3 the" apertures "I 5 'and'into the*disconnecte cavities 3i Normally such"Inaterial harderis rapidly and the dies c'anbe removedirnniediatelyL hav'ef used my'inventionwith a'var iet'y of plastics- -and have had very" satisfactoryresults with; all 'of them. I

Aluminum is a cus'torna'y material for form- :ing'the cover plateslfl "as it is iiglft and easii-y f :manufactured into desired shapes- A customary f working pressure in "such-injection:lnoidirig is tentons' or thereabout's: It fis' o,bviou the such f a pressure upon asheet of light"aluminum-would radically deform it, "it not completelyishe ar it :two. In order to "avoid iiijury'fto "the inc auntim ting the two dies'by tile-exactthickness-of the .material used in the "mounting plate-+8.

\while the dies are held in spaced relationshipby- :a force sufiicientto overeomethepiessare of ten "tons with which the' plastic -is injected; the pres B sure-of each die against th plateie mud-r less. In fact, the plate is held-firmly bet-weerrthedies; but-the pressure against the plate' is insufficient to either deform theplate or to injure the pain'ted surface [I thereon. ---Asa matter o'f-'-fact, the* characters are formedwitha firm fit i the dlesagainst the plate';-'especia-llywhen w "iikle p'ain finish 1s used. --When-a wrinkle a-i' 't" used; the depressions iii-the pai 'ntfi-ni may be .001 of an inc-hperinit' the escape' of gasi I Thus, it is'unnecessary"to prov e- 'the die' fl wit gas'ventsa slwouldprdinarily e= reqiui w w vioiis'ly," the dies should 1o' efj'accu ate1y iorr'r' ed'tw fit the curvature of the mountiniplated'fi. l

may later be drilled, or otherwise provided in the ltV-is less likelihood of deforming the plate. In additiqn:thezedsesaretfin enough to permit the escape of gas from the interior of the mold thro gh the creyices the wrinkled finish. This edge ot extelifiaround each individual "on jIt 'is "uflijcient if it extends around the? irii'a. Thus it is necessary to relieve the'idieibetweemthe separate characters.

I .,n.1ight Ipention in this connection that when mature and the newly formed insignia are z ved ro t -me d it w be s th t th heated'fplastie" has s r-perecrtnw paint 31 th portion covered-bi ths dies- It is for this'" 1 that I desire the edge of the die to be as 's'm as p'os'sibler Howeverfiafter cooling' -f'or' an ho or isothepainthas returned "to practically 7 original c'onditionandfcolorand itrequire's a very close scrutiny to dete nef any diiference be the plate. 7 4

It is known in the'prior art that'the'mold be finished "in a va twqi 11. 33. as, o 21 a variety of pleasing "eilejcts onth v finished'char Thus I arnabl'etoquiciil of very' pleasingap eara h v w i y ent 0 1ti p ti) rpladaa f signia without refinishing" the mounting as sometimes is necessary when the insig A dam a'ge'dbyanextreme force'or'fire; 'With y invention, the insignia "can be removed by} lire ing the backingplate 2| awayfromq'the'fplat with chisel "andfthen dr h insignia, n wp aqanb mo ded 9 E11, p afewithoutthefli fii f efiiiishinst t ute". side'nf-themountingfplat. u I w This. p o s p ovid s iaf simple i't etho df" me," "f'forjapplgiing' a plurality of fsepa'ra'te' disco. fiectd,iic aratj sifori e slit form. insignia. It is obvious thatjthesev'eralj'cha acters 28 extend throughthefplate' itselffandar integral witfi'the" backing piece 21 fwherebjfth individual characters cannotfbe removed "fro the mounting plat 'by 'breakifngfof "t confieictingbars Ir stems, .Wh'ichf'e'xteir'id throng bem I e. l l a Another advantage of invention lies th fact that the various: [characters can be small than s othe w se p a ti al-s: n. he p or a t t ep a or .s r pthad to h fair -lar e size. rderto prcvi eh senn hand ing: Wfihmy: i vention; handling. of preformed;- =na-rne is t; necessary; so that ithe-nnl-yF practical -eonsideras tion is that the holes or aperturesa-t iithroug h the mounting plate'be sufiiciei itly 'largelto provide for' of any size to suit ones taste, so long as they are larger than an aperture of .020 of an inch.

I claim:

1. The method of affixing separated characters of an insignia to an article which comprises providing a plurality of apertures through the article within the outline of each of the characters in a zone in which the article is of substantially uniform thickness, applying a die formed with disconnected characters against one side of the article at said zone and a second die formed with a single channel against the other side of the article with said channel being substantially parallel to said plate and substantially coextensive with said zone, said dies being separated by an external spacing means a distance equal to the thickness of the article and the first die contacting said plate only over a narrow marginal area around said insignia, injecting a hardenable plastic material into the second die under suflicient pressure to force such material through 7 said second die, said apertures, and into the formed with the insignia against one side of the article at said zone, said die engaging said article with a narrow face of a width of the order of about A,; to about a; of an inch, applying a second die formed with a concavity substantially coextensive with said zone and sufficiently large to cover said apertures against the inside of the article at said zone, injecting a hardenable plastic material into the second die under suflicient pressure to force such material through said second die, said apertures, and into the said first die. and thereafter removing said dies.

3. A compound die for aflixing an insignia of hardenable plastic material to a perforated article of stable material of substantially uniform thickness which comprises an outer die element adapted to contact the outer face of said article, said element having formed therein the separated characters of such insignia and having a narrow face thereon of a width of the order of about to about l; of an inch immediately adjacent said insignia, and an inner die element having a single channel in opposed relation to the characters of said face element, said channel being substantially coextensive with said characters considered collectively, means for injecting plastic material into the channel of said second element and spacing means separating said elements by the thickness of said article.

4. The method of aifixing characters of an insignia to an article provided on one side with a wrinkled paint finish which comprises providing a plurality of apertures through the article within the outline of each of the characters, applying a die formed with characters against said one side of the article and a second die formed with a single channel against the other side of the article, said dies being separated by an external spacing means a distance equal to the thickness of the article and the first die contacting the wrinkled paint finish of said plate only over a narrow marginal area around said insignia, injecting a hardenable plastic material into the second die under suiiicient pressure to force such material through said second die, said apertures, and into the several disconnected portions of said first die to thereby expel gas from said dies through the vents provided between said wrinkled paint finish and said narrow surface of said first die, and thereafter removing said dies.

ROY J. RENHOLTS.

REFERENCES CITED The following references are of record file of this patent:

UNITED STATES PATENTS in the 

3. A COMPOUND DIE FOR AFFIXING AN INSIGNIA OF HARDENABLE PLASTIC MATERIAL TO A PERFORATED ARTICLE OF STABLE MATERIAL OF SUBSTANTIALLY UNIFORM THICKNESS WHICH COMPRISES AN OUTER DIE ELEMENT ADAPTED TO CONTACT THE OUTER FACE OF SAID ARTICLE, SAID ELEMENT HAVING FORMED THEREIN THE SEPARATED CHARACTERS OF SUCH INSIGNTA AND HAVING THE NARROW FACE THEREON OF A WIDTH OF THE ORDER OF ABOUT 1/16 TO ABOUT 1/32 OF AN INCH IMMEDIATELY ADJACENT SAID INSIGNIA, AND AN INNER DIE ELEMENT HAVING A SINGLE CHANNEL IN OPPOSED RELATION TO THE CHARACTERS OF SAID FACE ELEMENT, SAID CHANNEL BEING SUBSTAN- 